Chapter 4 - Cell Structure Flashcards
ribosomes (function, composition, and where found)
- Function: The cell’s protein synthesis “machinery”.
- Composition: Ribosomal RNA (rRNA) and proteins
- Found: on rough ER, in the cytoplasm, and associated with membranes
plasma membrane
A phospholipid bilayer that separates a cell from its surroundings. (Embedded proteins allow it to interact with its surroundings.)
Mathias Schleiden & Theodor Schwann
Proposed the Cell Theory in 1839
Robert Hooke
Discovered the cell in 1665 through a cross-section of a cork.
Cell Theory (as proposed by Schleiden and Schwann in 1839)
- All organisms are composed of cells.
- Cells are the smallest living things.
- Cells arise only from pre-existing cells.
(All cells today represent a continuous line of descent from the first living cells.)
nucleus
- stores the genetic material of the cell in the form of multiple, linear chromosomes
- surrounded by a nuclear envelope composed of 2 phospholipid bilayers
mitochondrion
- The “power house” of the cell - generates ATP.
- Contains its own DNA.
- -surrounded by 2 membranes:
- smooth outer membrane
- folded inner membrane with layers (called cristae)
lysosome
- The “trash can” of the cell.
- membrane bound vesicles containing digestive enzymes to break down macromolecules
- destroy cells or foreign matter that the cell has engulfed (by phagocytosis)
Golgi apparatus
- The “shipping and receiving” department of the cell.
- flattened stacks of interconnected membranes
- packaging and distribution of materials to different parts of the cell
- synthesis of cell wall components
endoplasmic reticulum (generic function and composition)
- Functions: Synthesize proteins and fats, detoxify foreign substances, store calcium
- Composition: phospholipid bilayer embedded with proteins
chromosome
Linear structures in the nucleus that store the genetic material of the cell.
chromatin
In chromosomes – DNA organized with proteins.
Discovered the cell in 1665
Robert Hooke
Proposed the Cell Theory in 1839
Mathias Schleiden & Theodor Schwann
The cell’s protein synthesis “machinery”.
Ribosomes
Cell Theory: All cells have certain structures in common
- genetic material – in a nucleoid or nucleus
- cytoplasm – a semifluid matrix
- plasma membrane – a phospholipid bilayer
A phospholipid bilayer that separates a cell from its surroundings. (Embedded proteins allow it to interact with its surroundings.)
Plasma membrane
- stores the genetic material of the cell in the form of multiple, linear chromosomes
- surrounded by a nuclear envelope composed of 2 phospholipid bilayers
Nucleus
The “power house” of the cell - generates ATP.
Mitochondrion
The “trash can” of the cell.
Lysosome
The “shipping and receiving” department of the cell.
Golgi apparatus
Synthesizes proteins and fats, detoxifies foreign substances, stores calcium
Endoplasmic reticulum
Rough endoplasmic reticulum (why “rough”, function)
- “Rough” due to embedded ribosomes in the membranes.
* Function: synthesis of proteins to be secreted, sent to lysosomes or plasma membrane.
Smooth endoplasmic reticulum (why “smooth”, function)
- “Smooth” due to few embedded ribosomes in the membranes.
- Functions:
- synthesis of membrane lipids
- calcium storage
- detoxification of foreign substances
Linear structures in the nucleus that store the genetic material of the cell.
Chromosome
In chromosomes – DNA organized with proteins.
Chromatin
Centriole
Barrel-shaped organelles found in the cells of animals and most protists, near the nuclear membrane. (Lacking in plants.)
Centrosome
- Microtubule-organizing centers.
* Responsible for the reorganization of microtubules that occurs during cell division.
Centromere
The point of constriction on the chromosome containing repeated DNA sequences that bind specific proteins.
Chromatid
One of two (sister) replicated chromosome strands, held together at their centromeres by cohesion proteins after replication.
The point of constriction on the chromosome containing repeated DNA sequences that bind specific proteins.
Centromere
One of two (sister) replicated chromosome strands, held together at their centromeres by cohesion proteins after replication.
Chromatid
Microtubule-organizing centers.
Centrosome
Barrel-shaped organelles found in the cells of animals and most protists, near the nuclear membrane.
Centriole
